Re: [PATCH 01/10] staging: slicoss: slic.h: add a macro IOMEM_GET_FIELDADDR to fix sparse warnings

[Greg KH]

On Tue, Sep 13, 2016 at 07:59:50PM -0700, Peng Sun wrote:
> Signed-off-by: Peng Sun <sironhide0null@xxxxxxxxx>
> ---
>  drivers/staging/slicoss/slic.h | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/staging/slicoss/slic.h b/drivers/staging/slicoss/slic.h
> index fe1d2ce..7c23190 100644
> --- a/drivers/staging/slicoss/slic.h
> +++ b/drivers/staging/slicoss/slic.h
> @@ -539,6 +539,13 @@ static inline void slic_flush_write(struct adapter *adapter)
>  	ioread32(adapter->regs + SLIC_REG_HOSTID);
>  }
>  
> +#define IOMEM_GET_FIELDADDR(base, member)				\
> +({									\
> +	char __iomem *_base = (char __iomem *)base;			\
> +	_base += offsetof(typeof(*base), member);			\
> +	(void __iomem *)_base;						\
> +})
> +
>  #define UPDATE_STATS(largestat, newstat, oldstat)                        \
>  {                                                                        \
>  	if ((newstat) < (oldstat))                                       \
> -- 
> 2.7.4

Wait, what does this patch on its own do?  Why create this macro?

greg k-h